Do Dogs Poop in Alignment with Earth’s Magnetic Field?
There’s been quite a bit of press lately about dogs’ lavatory habits, and how they relate to the magnetic field produced by the Earth. But is it really true that dogs prefer to poop in the direction of the magnetic North and South poles? And if so, why would researchers care?
What did the Researchers Say?
Unsurprisingly, the researchers were not principally interested in doggy defecation habits. They were looking instead for evidence of magnetoception – simply, the ability of an animal to detect or sense a magnetic field. It’s well known to most that homing pigeons are magnetoceptors, and that they use this ability as we might use a compass when we are finding landmarks on a map. It’s not clear exactly how this sense works – the two main candidates are either the creation of free-radicals from proteins when struck by light, which align with the local magnetic field, or simply the presence of magnetic minerals like magnetite within the animal itself (the interested can read more on this here).
There are signs that animals closely related to the dog, such as wolves, are magnetoceptors. In some cases, the animals are believed to be magnetosensitive simply because of their superior homing range requiring the ability to know where magnetic north is (this line of reasoning concerns me a little, as it seems like an example of the post hoc ergo propter hoc fallacy). In other cases, there is more substantial evidence that the animals are capable of magnetoception (the red fox being an example).
In any case, there is a groundswell of evidence and suggestive behaviour that makes it sensible to wonder if dogs could be magnetosensitive. The researchers attempted to find this out by investigating canine behaviour during a variety of activities (resting, feeding and excreting). From these observations, they believed that excreting
appeared to be most promising with regard to obtaining large sets of data independent of time and space, and at the same time it seems to be least prone to be affected by the surroundings.
This is important. Dogs will spend a penny almost anywhere, whereas they will tend to rest and feed in the same places, introducing a bias (if the bed aligns North-South, so will the dog). Note here that “excreting” includes defecation, urination and marking their territory. The researchers looked at how dogs behaved in “calm” periods where the magnetic field stayed roughly fixed, and in periods where the magnetic field oscillated and changed. The researchers weren’t actually changing the magnetic field themselves – the Earth’s magnetic field naturally fluctuates for a variety of reasons, for example because charged particles in the ionosphere produce currents, or as a result of solar flares.
When the dogs did their business, the researchers measured the angle they adopted relative to the Earth’s magnetic field, and looked at the average alignment. When the magnetic field was calm, the researchers found the dogs’ typical alignment was very much with magnetic North or South. If the magnetic field fluctuated, then the alignment was less focused towards North/South.
These results are consistent with the dogs being sensitive to the local magnetic field (either on a conscious or unconscious level). One might argue that the reason for the alignment is to avoid being dazzled by the Sun while carrying out an activity that leaves the dog vulnerable to attack. The researchers believe this is not the case, as sometimes danger may come from the Sun’s direction. They also note that the dog’s preference does not change during the day. For some dogs they possessed more than 5 individual samples of behaviour, and over the course of the day the dog maintains its preferred axis, which is not consistent with the dog pointing away from the Sun.
On the other hand, the dog’s magnetoception (if it possesses it) does not appear to be particularly effective in general. When the researchers pooled all the data (calm and not-calm magnetic fields), they saw no evidence of alignment at all, meaning that dogs can only rely on this sense if the magnetic field behaves itself, which only happened during around a third of the researcher’s observations.
It also means that if you own a dog, you are probably unlikely to notice any alignment, unless you’re willing to only note your pup’s pooping practices when you’ve previously measured a stable magnetic field.
Scatological jokes aside, the researchers did uncover a link between magnetic fields and dog behaviour. As with all correlations, this does not mean causation – dogs aligning with the magnetic field is evidence for magnetoception, not proof. More study is needed, with larger samples (a total of only 70 dogs were involved in the study, located in the Czech Republic and Germany), and these future studies must be careful as to how they collect their data – for example, the researchers were careful to not count events where nearby structures could provide a template for alignment, such as roads, buildings or power lines.
What did the Media Say?
Googling this story results in pages and pages of hits (out of recent news alone, there are nearly 4,000 hits). The vast majority mention “poop” in the headline, because apparently that’s how to get readers (as supported by you reading this article). The study’s outcome regards magnetic sensitivity, but it’s fairly clear that many media outlets regard this as a water cooler story, rather than a serious scientific result. Specialist outlets like ScienceDaily rise above it all, downplaying the activity the dogs were engaged in.
Semantics is important here. Reuters state that “dogs use the magnetic field to align their position while defecating”, which implies the mechanism is applied consciously by the dog. The researchers admit they don’t know whether the alignments are conscious or not, and as a result they’re not sure why the dogs align at all.
The Guardian‘s blog is in-depth, and includes figures from the paper as well as linking to the article.
Motherboard cheerfully describes the phenomenon thus:
What dog owners witness is a small and furry version of the aurora borealis and a link between species and environment that’s as holistic and beautiful as a dog pooping can be.
As amusing as the prose is, with my pedant’s hat on I must note that (as I’ve already said) dog owners are unlikely to witness this event. However, they do link to the journal article, and the Facebook comments below the piece are hilarious.
V. Hart, P. Nováková, E.P. Malkemper, S. Begall, V. Hanzal, M. Ježek, T. Kušta, V. Němcová, J.Adámková, K. Benediktová, J. Červený, H. Burda, (2013) “Dogs are sensitive to small variations of the Earth’s magnetic field”. Frontiers in Zoology vol 10, article 80. doi: 10.1186/1742-9994-10-80